1. Field of the Invention
The invention relates to a Liquid Crystal Display (LCD) connection for connecting an LCD to a printed circuit board (PCB) in a communication unit.
2. Description of Prior Art
A connection between an LCD and a PCB in a communication unit is in many cases exposed to mechanical and other stresses, and specially when located in a communication unit that stress can be harmful to the connection between the LCD and the PCB. This is due to how a user handles his/her communication unit. It is not unusual that it is handled quite roughly and it might easily be dropped and thereby exposing the connection to stress. To reduce the of cost of assembling a communication unit it should be easy to assemble and also be possible to dismantle, which gives another set of demands on the connection between the LCD and the PCB.
In conventional solutions the LCD is provided with indium tin oxide (ITO) pads that electrically connects the LCD to a connector, and through that the connector connects to the PCB. The ITO pads are sensitive to contact with the surrounding and might easily react with the surroundings. One known way to avoid this is to attach the connector directly to the LCD, covering the ITO pads and thereby protecting them. Another solution is to cover the ITO pads with a metal film that protects the ITO pads.
U.S. Pat. No. 5,270,848 shows a liquid crystal apparatus that includes a laminated film made of an ITO film having a surface and a metal film on the surface. The connection electrode has been attached directly to the ITO film.
U.S. Pat. No. 6,025,644 shows a liquid crystal display device having input connection terminals connecting to output connection terminals using an Anisotropic conductive film (ACF) as binding. The output connection terminals are connected to a flexible printed circuit (FPC) using an elastic connector, i.e. a rubber connector. The FPC is connected to a PCB by inserting one end of the FPC into a connector on the PCB.
There are many ways to solve the connection problem between an LCD and a PCB, like having a fixed connection that can withstand any mechanical or other stress, but in most cases that will be avoided in the assembly of electronic products. The cost of assembling a fixed connection is too high.
An object of the invention is to provide an LCD connection for connecting an LCD to a PCB in a communication unit that allows the communication unit to be exposed to mechanical and other stresses while maintaining contact between the LCD and the PCB.
According to the claimed invention this objective is obtained by an LCD connection including an LCD provided with a plurality of connecting pads, a PCB is also provided with a plurality of connecting pads and a connector connecting said LCD to said PCB, where said connector includes springy metal parts between the connecting pads to establish contact with the LCD and the PCB.
Another object of the invention is to provide an LCD assembly for a communication unit that can easily be mounted and dismantled, but still remain reliable.
According to the claimed invention this objective is obtained by an LCD connection including an LCD having Indium Tin Oxide (ITO) pads covered by an Anisotropic Conductive Foil (ACF) layer, Double Flexible Printed Circuits (DFPC), a spring connector having springy metal ends and a PCB, where the spring connector is flexibly mounted on a lightguide that holds the LCD and the PCB together.
Yet another objective of the claimed invention is to provide a method for connecting an LCD to a PCB in a communication unit.
According to the claimed invention this objective is obtained by using a connector that is flexibly mounted between the LCD and the PCB and having conductive layer applied on the LCD to create a reliable connection.